When you are signed in to FASmail Web Mail interface (https://mail.ubc.ca), click on the avatar icon (blank head, or a picture), at the top right. Select "Open another mailbox" from the drop down menu.

In the prompt that appears, start typing the email address of the mailbox you want to open. If the name does not autofill, type it in and select "Search Directory" to find the mailbox.

One you have selected the correct mailbox, click Open to be brought to a new window with the other mailbox.

If you know you will be accessing the shared mailbox often, you can bookmark the URL for future use.

Alternative Method

You can right-click your name on the left hand side and click 'Add shared folder.'

 In the prompt that appears, start typing the email address of the mailbox you want to open and press enter. If the name does not autofill, type it in and select "Search Directory" to find the mailbox.

Click add to add the shared mailbox to your FASmail account. The shared mailbox will appear under your main mailbox.